Study On Pyrolysis Character Of Agricultural Wastes

Agricultural wastes are the valuable resource in our country, they can be converted into biomass energy in various ways to reduce our reliance on fossil energy, and help to protect the environment, so the reasonable use of this part of resources is important. Pyrolysis technology of agricultural wastes is widely applied to converting and utilizing bio-energy, which need us to know more about the pyrolysis characteristics of various agriculture materials. Then agricultural waste resources will be more fully developed.This paper studied on 12 types of agricultural and woody wastes which take a large amount in our country, the thermogravimetry analysis experiments were carried in nitrogen atmosphere with two selected heating rate which was 10℃/min and 20℃/min respectively. Firstly, the crude fiber and lignin content of that 12 kinds of agricultural waste materials was measured in the cellulose detector. The results showed that lignin content of peanut shell, fir branche, cotton stalk, bamboo, camphor tree, rape bar is at a higher level; Corn cob, rice straw, corn stalk, wheat straw is lower with the crude fiber content. And the others contain more crude fiber the percentage content of which are higher than 50%.On the analysis of TG and DTG curves, we may see the pyrolysis process of agricultural waste materials can be divided into four stages. The weight loss stage of pyrolysis process mainly concentrated in the temperature range of 200℃-440℃. Different materials show different characteristics. The temperature corresponding to the maximum pyrolysis rate of bamboo, fir tree, parasol stick, camphor tree is higher, relatively lower with Straw wastes. In addition, DTG curves of parasol sticks, peanut vine, camphor tree, rape rod have obvious side apex.Finally, respectively, differential method and integral method were used to figure out the kinetic parameters of all the kinds of materials, and then the results were analyzed and solved. There were little difference between the activation energy of different materials with which crude fiber and lignin content of no significant relationship. Different kinds of agricultural waste have some common characteristics, and under certain conditions they can be transformed and used together.